I attended the OpenMIC BarCamp event in Bath last week and was interested to learn about mobile widgets. Mobile widgets are basically mobile apps build with web technologies. They come in different flavours but all are a collection of JavaScript, CSS and image files together with an HTML file. These files are then packaged in a zip file with an XML descriptor (a bit like a war) and can be deployed to a mobile phone. I just deployed my by sending the file via Bluetooth. The application then can be started like a normal app although it is effectively a local web site running the browser full screen. Obviously the big wins here are that the JavaScript code is cross platform and the deployment does not require an app store.

As GWT generates JavaScript code I thought it would be suitable for packaging up as a mobile widget so as I have a Nokia phone I took the Nokia WRT kit and gave it a go. The results were very promising and my test GWT app worked very well on my phone, a Nokia E72.

The problem is of course that you cannot use RPC calls as you don’t have a server. However you can use JSONP to talk to a remote server which is perfectly adequate and this works well so far too. Using GWT to produce mobile widgets seems to have a lot of potential for creating mobile apps very quickly and with little pain. It would be great to hear from anyone else who is using this approach for mobile apps and any problems they encountered that I haven’t yet.